Hello everybody.

First of all I apologize for my english skill, will try the best as I can.

My 1st post here -unfortunately for bad reason and will much appreciate if someone can give me some advise.

So, my car is C200K Petrol, Manual, 2001, 70000 miles.

Here is the problem.
Two months ago the engine light on the display come ON. The dealer set Air Mass Sensor is faulty.
New part from Mercedes is about £300, so I bought from e-bay brand new coming from Chine for £40.
Replaced it (everything was ok) and after 10 days the light again ON.
The dealer check again and found that the magnet (in front of engine) and plug was in oil. So new magnet and good cleaning sort the problem for 2 days (about 100 miles), and again the light.
After that I left the car for 3 days to dealer to check, try and replace what ever they think.
So they replaced two sensors (presure sensors) which I don't know. They just set there are exactly the same parts number but in different place (one is close to the Air Mass sensor).
They test the car for 200 miles (3 days) without any problems.
Yesterday I collected the car and unfortunately today (after 30 miles) -again the light.

Tomorow again I will visit the dealer, but I'm worry how far this problem can go.
Is the way to solve this problem is to replace everything possible?

Once again I will much appreciate for any advises. Thank you!

 

there is a problem with the wiring harness and oil getting into the wire harness from the Cam advance magnet. there is an update harness which the dealer can get or should have in stock. the new harness just goes inline from the magnet to the harness and is supposed to keep the oil from running into the wire harness. youll get oil into the engine control module and other places. im not sure about your engine over there since here in USA we dont have that motor so im not sure if its the exact same issue.

 

Thank you chassis221 for the quick response.
But now the magnet is new and I already cleaned all the cable plugs with BrakeCleaner (thats what the dealer recomended).
So i can't understand why they replaced the pressure sensors, is it true that there are two pressure sensors!?
I will see tomorrow what will happen.

 

even after all the oil is cleaned out you still might have some oil in there and you might have to wait till the rest has come out. im not sure on your engine about the magnents. but i believe there are 2.

 

I've been already twice to the dealer in the last two weeks.
They've replaced (not sure for the name) the parts on the top of the sparking plugs and topped up the petrol with some cleaner.
Unfortunately again LIGHT.

I checked all the plugs in MAS sensor, CAM (magnet) sensor and O2 sensor - everything looks OK without any oil.
Just don't know what to do now.

 

I am having the same issue. I have an 03 C230 Kompressor and the Air Mass Sensor was replaced and within hours the check engine light came back on however the sulfur smell that I had before this was replaced is gone. The problem is, I need a NYS inspection as it expired over a month ago and you cannot inspect with the check engine light on. My husband is a mechanic (American Cars) but has lots of experience with imports and is stumped..the computer states the part we replaced is the problem.. but how can that be! He is at a loss...we even took to a Mercedes dealer and they seem to be stumped!

 

GOOD NEWS (fingers cross)

Now about two months latter and 1500 miles - everything looks to be OK.
So, what was the problem - dirty throttle body.
After good cleaning and even I put back the old original Air Mass - the Light has gone.
Just hope no problems for many years.
Thanks to everyone and wish to all of you safe journey.